TABLE 7—MODEL 376CAV ORIFICE SIZE† AND MANIFOLD PRESSURE FOR CORRECT INPUT (CONTINUED)
(TABULATED DATA BASED ON 23,000 BTUH PER BURNER, DERATED 4 PERCENT FOR EACH 1000 FT ABOVE SEA LEVEL)*
ALTITUDE
RANGE
(FT)
AVG GAS
HEAT VALUE
AT ALTITUDE
(BTU/CU FT)
SPECIFIC GRAVITY OF NATURAL GAS
0.58
0.60
0.62
0.64
0.66
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
U.S.A.
Only
5001
to
6000
700
43
3.7
43
3.8
42
3.2
42
3.3
42
3.4
725
43
3.4
43
3.6
43
3.7
43
3.8
42
3.2
750
43
3.2
43
3.3
43
3.4
43
3.5
43
3.6
775
43
3.0
43
3.1
43
3.2
43
3.3
43
3.4
800
43
2.8
43
2.9
43
3.0
43
3.1
43
3.2
825
43
2.7
43
2.7
43
2.8
43
2.9
43
3.0
850
43
2.5
43
2.6
43
2.7
43
2.8
43
2.8
875
43
2.4
43
2.4
43
2.5
43
2.6
43
2.7
900
43
2.2
43
2.3
43
2.4
43
2.5
43
2.5
925
43
2.1
43
2.2
43
2.3
43
2.3
43
2.4
950
48
3.8
43
2.1
43
2.1
43
2.2
43
2.3
975
48
3.6
48
3.7
43
2.0
43
2.1
43
2.2
1000
48
3.4
48
3.5
48
3.6
48
3.7
43
2.1
ALTITUDE
RANGE
(FT)
AVG GAS
HEAT VALUE
AT ALTITUDE
(BTU/CU FT)
SPECIFIC GRAVITY OF NATURAL GAS
0.58
0.60
0.62
0.64
0.66
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
U.S.A.
Only
6001
to
7000
650
43
3.7
43
3.8
42
3.2
42
3.3
42
3.5
675
43
3.4
43
3.5
43
3.7
43
3.8
42
3.2
700
43
3.2
43
3.3
43
3.4
43
3.5
43
3.6
725
43
3.0
43
3.1
43
3.2
43
3.3
43
3.4
750
43
2.8
43
2.9
43
3.0
43
3.1
43
3.2
775
43
2.6
43
2.7
43
2.8
43
2.9
43
3.0
800
43
2.4
43
2.5
43
2.6
43
2.7
43
2.8
825
43
2.3
43
2.4
43
2.5
43
2.5
43
2.6
850
43
2.2
43
2.2
43
2.3
43
2.4
43
2.5
875
43
2.0
43
2.1
43
2.2
43
2.3
43
2.3
ALTITUDE
RANGE
(FT)
AVG GAS
HEAT VALUE
AT ALTITUDE
(BTU/CU FT)
SPECIFIC GRAVITY OF NATURAL GAS
0.58
0.60
0.62
0.64
0.66
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
U.S.A.
Only
7001
to
8000
625
43
3.4
43
3.6
43
3.7
43
3.8
42
3.2
650
43
3.2
43
3.3
43
3.4
43
3.5
43
3.6
675
43
3.0
43
3.1
43
3.2
43
3.3
43
3.4
700
43
2.7
43
2.8
43
2.9
43
3.0
43
3.1
725
43
2.6
43
2.6
43
2.7
43
2.8
43
2.9
750
43
2.4
43
2.5
43
2.6
43
2.6
43
2.7
775
43
2.2
43
2.3
43
2.4
43
2.5
43
2.5
800
43
2.1
43
2.2
43
2.2
43
2.3
43
2.4
825
48
3.7
43
2.0
43
2.1
43
2.2
43
2.2
850
48
3.5
48
3.6
48
3.7
43
2.1
43
2.1
ALTITUDE
RANGE
(FT)
AVG GAS
HEAT VALUE
AT ALTITUDE
(BTU/CU FT)
SPECIFIC GRAVITY OF NATURAL GAS
0.58
0.60
0.62
0.64
0.66
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
U.S.A.
Only
8001
to
9000
600
43
3.2
43
3.3
43
3.4
43
3.5
43
3.6
625
43
3.0
43
3.1
43
3.2
43
3.3
43
3.4
650
43
2.7
43
2.8
43
2.9
43
3.0
43
3.1
675
43
2.5
43
2.6
43
2.7
43
2.8
43
2.9
700
43
2.4
43
2.4
43
2.5
43
2.6
43
2.7
725
43
2.2
43
2.3
43
2.3
43
2.4
43
2.5
750
43
2.0
43
2.1
43
2.2
43
2.3
43
2.3
775
48
3.6
48
3.7
43
2.1
43
2.1
43
2.2
800
48
3.4
48
3.5
48
3.6
48
3.7
43
2.0
* For size 060135 only, input is 22,500 Btuh per burner. Deduct 0.1-in. wc from manifold pressure shown in table. Change orifice size if manifold pressure falls below 3.2-in.
wc on altitudes up to 2000 ft, otherwise change orifice size if manifold pressure falls below 2.0-in. wc.
†Orifice sizes shown in SHADING are factory installed.
—17—
